package thread;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * 线程池
 * 线程池是线程的管理机制，主要解决两个问题:
 * 1:重复使用线程
 * 2:控制线程数量
 */
public class ThreadPooDemo {
    public static void main(String[] args) {
        //创建线程池
        ExecutorService threadPool
                = Executors.newFixedThreadPool(3);
        //指派任务
        for(int i=0;i<5;i++){
            Runnable r = new Runnable() {
                @Override
                public void run() {
                    Thread t = Thread.currentThread();
                    System.out.println(t.getName()+":正在执行一个任务...");
                    try {
                        Thread.sleep(5000);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    System.out.println(t.getName()+":执行任务完毕了！");
                }
            };
            threadPool.execute(r);
            System.out.println("将任务交给了线程池");
        }
//        threadPool.shutdown();
        threadPool.shutdownNow();
        System.out.println("线程池关闭了");
    }
}
